'Ultrawideband' Could Be Future of Medical Monitoring

Source: ScienceDaily

ScienceDaily (June 16, 2011) — New research by electrical engineers at Oregon State University has confirmed that an electronic technology called "ultrawideband" could hold part of the solution to an ambitious goal in the future of medicine -- health monitoring with sophisticated "body-area networks." Such networks would offer continuous, real-time health diagnosis, experts say, to reduce the onset of degenerative diseases, save lives and cut health care costs.
Some remote health monitoring is already available, but the perfection of such systems is still elusive.
The ideal device would be very small, worn on the body and perhaps draw its energy from something as minor as body heat. But it would be able to transmit vast amounts of health information in real time, greatly improve medical care, reduce costs and help to prevent or treat disease.
Sounds great in theory, but it's not easy. If it were, the X Prize Foundation wouldn't be trying to develop a Tricorder X Prize -- inspired by the remarkable instrument of Star Trek fame -- that would give $10 million to whoever can create a mobile wireless sensor that would give billions of people around the world better access to low-cost, reliable medical monitoring and diagnostics.
The new findings at OSU are a step towards that goal.
"This type of sensing would scale a monitor down to something about the size of a bandage that you could wear around with you," said Patrick Chiang, an expert in wireless medical electronics and assistant professor in the OSU School of Electrical Engineering and Computer Science.
"The sensor might provide and transmit data on some important things, like heart health, bone density, blood pressure or insulin status," Chiang said. "Ideally, you could not only monitor health issues but also help prevent problems before they happen. Maybe detect arrhythmias, for instance, and anticipate heart attacks. And it needs to be non-invasive, cheap and able to provide huge amounts of data."
Several startup companies such as Corventis and iRhythm have already entered the cardiac monitoring market.
According to the new analysis by OSU researchers, which was published in the EURASIP Journal on Wireless Communications and Networking, one of the key obstacles is the need to transmit large amounts of data while consuming very little energy.
They determined that a type of technology called "ultrawideband" might have that capability if the receiver getting the data were within a "line of sight," and not interrupted by passing through a human body. But even non-line of sight transmission might be possible using ultrawideband if lower transmission rates were required, they found. Collaborating on the research was Huaping Liu, an associate professor in School of Electrical Engineering and Computer Science.
"The challenges are quite complex, but the potential benefit is huge, and of increasing importance with an aging population," Chiang said. "This is definitely possible. I could see some of the first systems being commercialized within five years." Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Oregon State University.

Team Reports Scalable Fabrication of Self-Aligned Graphene Transistors, Circuits

Source: ScienceDaily

ScienceDaily (June 16, 2011) — Graphene, a one-atom-thick layer of graphitic carbon, has the potential to make consumer electronic devices faster and smaller. But its unique properties, and the shrinking scale of electronics, also make graphene difficult to fabricate and to produce on a large scale. In September 2010, a UCLA research team reported that they had overcome some of these difficulties and were able to fabricate graphene transistors with unparalleled speed. These transistors used a nanowire as the self-aligned gate -- the element that switches the transistor between various states. But the scalability of this approach remained an open question.
Now the researchers, using equipment from the Nanoelectronics Research Facility and the Center for High Frequency Electronics at UCLA, report that they have developed a scalable approach to fabricating these high-speed graphene transistors.
The team used a dielectrophoresis assembly approach to precisely place nanowire gate arrays on large-area chemical vapor deposition-growth graphene -- as opposed to mechanically peeled graphene flakes -- to enable the rational fabrication of high-speed transistor arrays. They were able to do this on a glass substrate, minimizing parasitic delay and enabling graphene transistors with extrinsic cut-off frequencies exceeding 50 GHz. Typical high-speed graphene transistors are fabricated on silicon or semi-insulating silicon carbide substrates that tend to bleed off electric charge, leading to extrinsic cut-off frequencies of around 10 GHz or less.
Taking an additional step, the UCLA team was able to use these graphene transistors to construct radio-frequency circuits functioning up to 10 GHz, a substantial improvement from previous reports of 20 MHz.
The research opens a rational pathway to scalable fabrication of high-speed, self-aligned graphene transistors and functional circuits and it demonstrates for the first time a graphene transistor with a practical (extrinsic) cutoff frequency beyond 50 GHz.
This represents a significant advance toward graphene-based, radio-frequency circuits that could be used in a variety of devices, including radios, computers and mobile phones. The technology might also be used in wireless communication, imaging and radar technologies.
The UCLA research team included Xiangfeng Duan, professor of chemistry and biochemistry; Yu Huang, assistant professor of materials science and engineering at the Henry Samueli School of Engineering and Applied Science; Lei Liao; Jingwei Bai; Rui Cheng; Hailong Zhou; Lixin Liu; and Yuan Liu.
Duan and Huang are also researchers at the California NanoSystems Institute at UCLA.
The work was funded by grants from National Science Foundation and the National Institutes of Health.
The research was recently published in the peer-reviewed journal Nano Letters. Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of California - Los Angeles. The original article was written by Mike Rodewald.